Profiling with Flipper and React DevTools
Connect Flipper to a running app, use the React DevTools plugin to inspect the component tree, record a render trace, and identify which components re-render unnecessarily.
Why Performance Profiling Matters
React Native apps can suffer from dropped frames, slow list scrolling, long startup times, and excessive memory use — all of which frustrate users. Before optimizing, you must measure to understand where the bottleneck actually is, rather than guessing and making speculative changes.
The two primary profiling tools for React Native are Flipper (a native debugging platform) and React DevTools (which includes a component profiler). Used together, they give you visibility into both the JS thread performance and the component render tree.
Setting Up Flipper
Flipper is a desktop application by Meta that connects to running React Native apps over USB or a network and displays real-time debugging data. Download it from fbflipper.com and install it on your development machine.
Flipper works out of the box with React Native CLI projects on physical devices and simulators. For Expo apps, you need to use a development build (not Expo Go). Once connected, Flipper's sidebar shows available plugins including React DevTools, Network Inspector, Hermes Debugger, and Layout Inspector.
All lessons in this course
- Profiling with Flipper and React DevTools
- Memoization with React.memo, useCallback, useMemo
- FlatList Performance Tuning
- Bundle Size and Lazy Loading